| Popis: |
An apparatus designed to accelerate protons of a hydrogen plasma to energies of 1 kev or more by means of the radially converging magnetic piston of a longitudinal pinch has been constructed. A capacitor charged to voltages of up to 350 kv is discharged through the plasma, producing currents of up to 75 ka. The ringing frequency is 18 Mc, so that the rate of current rise is about 0.8 × 1013 amp/sec. Radially converging luminous fronts with maximum velocities in excess of 50 cm/μsec are observed and are interpreted as shock waves driven by a magnetic piston. Magnetic probe measurements and measurements of the electric field at the wall of the discharge tube show that much of the magnetic flux introduced during the first half‐cycle is trapped in the hot plasma. The effects of varying such parameters as the total current, the initial pressure of gas, the type of gas, and the frequency of the discharge have been investigated. The experimental results are interpreted in terms of the classical Rosenbluth‐Garwin theory of the pinch, which seems to correlate well with the observations. |
